Penicillin-resistant Streptococcus

Higher dose amoxicillin, amoxicillin-davulanate (eg., 90 mg/kg/day) is used for penicillin-resistant Streptococcus pneumoniae fluoroquinolones are avoided in pediatric patients because of the potential for cartilage damage however, their use in pediatrics is emerging. Doses shown are extrapolated from adults and will require further study. 

Treatment failure or prior antibiotic therapy in past 4-6 weeks High suspicion of penicillin-resistant Streptococcus pneumoniae... 

The emergence of multidrug-resistant Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), and vancomycin-resistant enterococci... 

Levofloxacin (1), the levo-isomer or the (5)-enantiomer of ofloxacin, received FDA approval in 1996 (Fish, 2003 Hurst et al., 2002 Mascaretti, 2003 Norrby, 1999 North et al., 1998). The initial approval covered community-acquired pneumonia, acute bacterial exacerbation of chronic bronchitis, acute maxillary sinusitis, uncomplicated skin and skin structure infections, acute pyelonephritis, and complicated urinary tract infections (North et al., 1998). Four years later, the levofloxacin indication list grew to include community-acquired pneumonia caused by penicillin-resistant Streptococcus pneumoniae. In addition, in 2002, nosocomial (hospital-acquired) pneumonia caused by methicillin-susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Haemophilus influenzae, Kliebsella pneumoniae, and Escherichia coli was added (Hurst et al., 2002). Finally in 2004, LVX was approved as a post-exposure treatment for individuals exposed to Bacillus anthracis, the microbe that causes anthrax, via inhalation (FDA, 2004). 

Staphylococcus aures (penicillin-sensitive) Staphyloccocus aureus (penicillin-resistant) Streptococcus pyogenes Streptococcus pneumoniae Enterococcus faecalis ... 

DalhoffA, etal. Penicillin-resistant Streptococcus pneumoniae review of moxifloxacin activity. Clin. Infect. Dis., 2001, 32 (Suppl. 1), S22-S29. 

Church D, et al. Efficacy of moxifloxacin in the treatment of acute bacterial sinusitis caused by penicillin-resistant Streptococcus pneumoniae. In 40th Interscience Conference on Antimicrobial Agents and Chemotherapy, Abstract 833. Toronto, 2000. 

A further mode of /S-lactam resistance is due to an alteration in the PBP s structure, resulting in ineffective binding of the antibiotic. Notable examples of this mode of resistance include methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae. 

Because of its potential toxicity, vancomycin is reserved for serious infections in which less toxic antibiotics are ineffective or not tolerated. Generally, vancomycin is administered intravenously because of poor intestinal absorption. It is the drug of choice for treating infections caused by methicillin-resistant staphylococci and penicillin-resistant Streptococcus pneumoniae. Vancomycin has been used to treat enterococcal infections because of their resistance to the P-lactam antibiotics, but most enterococci are now also resistant to vancomycin. Oral administration of rancomycin is important for treatment of some gastrointestinal infections such as pseudomembranous colitis caused by C. difficile. 

Methicillin-resistant strains of Staphylococcus aureus and S. epidermidis and penicillin-resistant Streptococcus pneumoniae have been isolated from ocular infections. Therefore treatment of ocular infections caused by these organisms might require use of vancomycin for resolution. Vancomycin is also recommended for empiric intra-vitreal and topical therapy in bacterial endophthalmitis and for parenteral therapy in moderate to severe preseptal cellulitis (see Table 11-1). 

Problems of cmtimicrobial resistance have burgeoned during the past decade in most coimtries of the world. Some resistant microbes are currently mainly restricted to patients in the hospitcil, e.g. MRSA, vancomycin-resistant enterococci (VRE), and coliforms that produce extended spectrum P-lactamases. Others more commonly infect patients in the community e.g. penicillin-resistant Streptococcus pneumoniae and multiply-resistant Mycobacterium tuberculosis. Evidence is accruing that the outcomes of infections with antibiotic resistant bacteria are generally poorer than those with... 

Others. Leoofloxacin (t) 7h) has greater activity against Streptococcus pneumoniae than ciprofloxacin and is used for respiratory and urinary tract infection. Moxifloxacin (t) 12 h) has strong anti-Gram-positive activity, and may prove useful for respiratory tract infections including those caused by atypical pathogens and penicillin-resistant Streptococcus pneumoniae. 

Fosfomycin is one of a few natural products containing a carbon-phosphorus (C— P) bond isolated from Streptomyces fradiae, Streptomyces viridochromogenes, and Streptomyces wedmorensis [73]. It was also isolated from Pseudomonas syringae and Pseudomonas viridiflava [74, 75], Fosfomycin is a highly effective antibiotic of low toxicity clinically utilized for the treatment of lower urinary tract infections [76] as well as methicillin-resistant [77] and vancomycin-resistant [78] strains of S. aureus. Moreover, fosfomycin is effective for the treatment of cephalosporin- and penicillin-resistant Streptococcus pneumonia [79] and ciprofloxacin-resistant E. coli [80], The antimicrobial activity of fosfomycin has been ascribed to the inactivation of UDP-GlcAAc-3-O-enolpyruvyltransferase (MurA), an essential enzyme that catalyzes the first committed step in the biosynthesis of peptidoglycan, the main component of the cell wall, by covalent alkylation of an active site cysteine [81]. 

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